Correlates and prevalence of insufficient 25-hydroxyvitamin D status in black and white older adults: the health, aging and body composition study.

OBJECTIVES: To determine the prevalence and correlates of vitamin D insufficiency in black and white older adults.
DESIGN: Cross-sectional.
SETTING: Health, Aging and Body Composition Study. PARTICIPANTS: Nine hundred seventy-seven black and 1,604 white adults aged 70 to 81. MEASUREMENTS: Logistic regression and classification and regression tree analysis were used to identify correlates of vitamin D insufficiency (25-hydroxyvitamin D (25(OH)D) <30 ng/mL) separately in blacks and whites.
RESULTS: The prevalence of 25(OH)D insufficiency was 84% in blacks and 57% in whites. Seventy-six percent of blacks and 56% of whites did not take a multivitamin; those who did not take a multivitamin were more likely to be vitamin D insufficient (odds ratio (OR)=5.17 (95% confidence interval (CI)=3.47-7.70) for blacks; OR=2.56, 95% CI=2.05-3.19 for white). Additional risk factors for vitamin D insufficiency were vitamin D-containing supplement use, female sex, and obesity in blacks; and winter season, low dietary vitamin D intake, obesity, type 2 diabetes mellitus, and female sex in whites.
CONCLUSION: Vitamin D insufficiency was more prevalent in blacks than whites. Not consuming a multivitamin increased the odds of vitamin D insufficiency in blacks and whites. Knowledge of additional risk factors such as dietary intake and comorbid conditions may help identify older adults who are likely to be vitamin D insufficient.